> For the complete documentation index, see [llms.txt](https://dev.guardian.hedera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dev.guardian.hedera.com/developer-tools-and-resources/api-reference/system-schema-apis/returns-schema-by-username-v2.md).

# Returns Schema by Username (Api-Version: 2)

**`GET /schemas/system/{username}`** — requires `Api-Version: 2` header

Returns all system schemas for the authenticated user. Version 2 fetches only the required schema fields (optimised payload) via `getSystemSchemasV2`. Only users with the Standard Registry role are allowed to make the request.

> **Note:** The `username` path parameter is kept for URL compatibility with existing clients. The server does not use this value when resolving the response — the returned system schemas are determined solely by the authenticated user and query parameters.

**Authentication:** Bearer token required (`Authorization: Bearer <token>`)

**Permission:** `Permissions.SCHEMAS_SYSTEM_SCHEMA_READ`

***

## Request

### Headers

| Header        | Value | Required | Description                                |
| ------------- | ----- | -------- | ------------------------------------------ |
| `Api-Version` | `2`   | Yes      | Enables V2 behaviour (optimised field set) |

### Path Parameters

| Parameter  | Type   | Required | Description                                              |
| ---------- | ------ | -------- | -------------------------------------------------------- |
| `username` | String | Yes      | Present for URL compatibility only; not used server-side |

### Query Parameters

| Parameter   | Type    | Required | Description                                                           |
| ----------- | ------- | -------- | --------------------------------------------------------------------- |
| `pageIndex` | Integer | No       | The number of pages to skip before starting to collect the result set |
| `pageSize`  | Integer | No       | The number of items to return                                         |

***

## Response

### Success Response

**Status:** `200 OK`

Returns an array of system schema objects containing only required fields. The total item count is provided in the `X-Total-Count` response header.

```json
[
  {
    "id": "f3b2a9c1e4d5678901234567",
    "uuid": "f3b2a9c1e4d5678901234567",
    "name": "Schema name",
    "description": "Description",
    "entity": "string",
    "iri": "string",
    "status": "string",
    "topicId": "f3b2a9c1e4d5678901234567",
    "version": "1.0.0",
    "owner": "string",
    "messageId": "f3b2a9c1e4d5678901234567",
    "category": "string",
    "documentURL": "https://example.com",
    "contextURL": "https://example.com",
    "document": {},
    "context": {}
  }
]
```

### Error Responses

| Status                      | Description               |
| --------------------------- | ------------------------- |
| `401 Unauthorized`          | Missing or invalid token  |
| `403 Forbidden`             | Insufficient permissions  |
| `500 Internal Server Error` | Unexpected server failure |